Hillary Rodham Clinton’s no-holds-barred attack on Rick Lazio marks a major shift in strategy for the first lady -and signals the end of an internal debate within her campaign.

After Lazio entered the race May 20, Clinton avoided a full-blown confrontation with the Long Island congressman – going after him bit-by-bit, one issue at a time.

Sources say Lazio’s candidacy created a division within the Clinton team between those who immediately wanted to slice and dice the newcomer and others who wanted her to hold off, at least for a while.

The prevailing opinion was that a tough attack might backfire, making her appear negative as a candidate with a fresh, new face was entering the race.

Clinton stuck to the cautious strategy that she employed against Mayor Giuliani, traveling across the state and sticking to her “message of the day” which usually included one attack against her GOP foe.

But four polls – which indicated the race is a statistical dead heat – changed all that.

The decision was finally made to have the first lady deliver a high-profile speech in which she would recite a litany of issues in which she differed with Lazio, arguing that he “has been a follower not a leader” during his eight years in Congress.

“People don’t know anything about him and when they learn these things, they don’t like it,” said one Clinton insider.

“Too many people still don’t have a favorable view of [Hillary] and they don’t know anything about [Lazio],” said another Clinton aide.

Clinton, who often had to be prodded by aides to attack Giuliani, could no longer hope her GOP foe would self-destruct like the mayor.

“You can’t realistically expect Lazio to be his own worst enemy,” said one Clinton insider.